Electrical Isolation Of Pulmonary Veins Research Articles

Hybrid Ablation of Atrial Fibrillation: A Contemporary Overview.

Electrical isolation of pulmonary veins (PVI) is the cornerstone of invasive treatment of atrial fibrillation (AF). However, arrhythmia-free survival of a PVI only approach is suboptimal in patients with persistent and long-term persistent AF. Hybrid AF ablation has been developed with the aim of combining the advantages of a thoracoscopic surgical ablation (direct visualization of anatomical structures to be spared and the possibility to perform epicardial lesions) and endocardial ablation (possibility to check line block, confirm PVI, and possibility to perform cavotricuspid isthmus ablation). Patient selection is of utmost importance. In persistent and long-term persistent AF, hybrid AF ablation demonstrated promising results in terms of AF free survival. It has been associated with a relatively low complication rate if performed in centers with expertise in hybrid procedures and experience with both surgical and endocardial ablation. Different techniques have been described, with different approaches and lesion sets. The aim of this review is to provide a state-of-the-art overview of hybrid AF ablation.

Multielectrode Contact Measurement Can Improve Long-Term Outcome of Pulmonary Vein Isolation Using Circular Single-Pulse Electroporation Ablation.

Background:Irreversible electroporation (IRE) ablation is generally performed with multielectrode catheters. Electrode-tissue contact is an important predictor for the success of pulmonary vein (PV) isolation; however, contact force is difficult to measure with multielectrode ablation catheters. In a preclinical study, we assessed the feasibility of a multielectrode impedance system (MEIS) as a predictor of long-term success of PV isolation. In addition, we present the first-in-human clinical experience with MEIS.Methods:In 10 pigs, one PV was ablated based on impedance (MEIS group), and the other PV was solely based on local electrogram information (EP group). IRE ablations were performed at 200 J. After 3 months, recurrence of conduction was assessed. Subsequently, in 30 patients undergoing PV isolation with IRE, MEIS was evaluated and MEIS contact values were compared to local electrograms.Results:In the porcine study, 43 IRE applications were delivered in 19 PVs. Acutely, no reconnections were observed in either group. After 3 months, 0 versus 3 (P=0.21) PVs showed conduction recurrence in the MEIS and EP groups, respectively. Results from the clinical study showed a significant linear relation was found between mean MEIS value and bipolar dV/dt (r2=0.49, P<0.001), with a slope of 20.6 mV/s per Ohm.Conclusions:Data from the animal study suggest that MEIS values predict effective IRE applications. For the long-term success of electrical PV isolation with circular IRE applications, no significant difference in efficacy was found between ablation based on the measurement of electrode interface impedance and ablation using the classical EP approach for determining electrode-tissue contact. Experiences of the first clinical use of MEIS were promising and serve as an important basis for future research.

It Is Necessary to Re-understand the Low-Voltage Area in Atrial Fibrillation Patients.

The presence of a low-voltage areas (LVAs) is a major feature of the progression of atrial fibrillation. Typically, the LVA is determined by invasive left atrial voltage mapping. In addition to pulmonary vein electrical isolation, Voltage-guided substrate modification by targeting LVAs in addition to PVI has been shown to be superior to conventional PVI “only” approaches regarding freedom from AF recurrences after ablation. Recent studies have found Atrial wall thickness correlates with low voltage areas, and the degree of atrial myocardial fibrosis can be better assessed by CT or MRI in combination with voltage mapping, which might help reduce the recurrence of AF after catheter ablation.

Acute safety and efficacy outcome of pulmonary vein isolation using pulsed field ablation technology

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Pulsed field ablation (PFA) is a new technology for electrical isolation of pulmonary veins (PVI) using electroporation for irreversible cell death. First data imply a very low complication rate in terms of esophageal lesion, phrenic nerve palsy and pulmonary vein stenosis. We present our datas of our first patients concerning acute safety and efficacy. Method 38 patients with paroxysmal and persistent atrial fibrillation (AF) consecutively underwent PFA ablation including complete PVI of all pulmonary veins in all cases (including 14 redo cases ), mean age 68,3 year, and a mean ejection fraction of 56 %, mean CHADSVASC Score 3. 19 patients had paroxysmal AF, in 21 patients additional posterior wall isolation was performed. Additional anatomical and voltage characterization with CARTO was performed before and after ablation. Post ablation, all patients underwent endoscopic evaluation of the esophagus and all eligible patients were screened for silent cerebral lesions (SCL) using cerebral magnetic resonance imaging (MRI). All acute procedure data and complications were documented. Results In all 38 patients effective PVI using only PFA catheter was achieved (100 %) within a mean procedure time of 81±15 min and a mean fluoroscopy time of 18± 5 min. In 2 patients left atrial macroreentrant tachycardia was effectively terminated with PFA pulses in the PV-mitral-annular isthmus region. In no patient an esophageal lesion could be detected (0%). Cerebral MRI was performed in 18 cases and revealed SCLs (47 %) in 5 patients (3 patients with multiple lesions, 2 patiens with 3 lesions, max size of 8 mm). No symptomatic complications including pericardial effusion or access site complications were noted. Conclusion PFA is a highly effective method for acute PVI. No relevant symptomatic complications were noted. Of note, no patient had esophageal injury related to the ablation but 40% of patients undergoing post-ablation MRI had documented SCE. Further data have to be collected to discuss these findings properly.

Novel cryo-balloon technology for a successful pulmonary vein isolation: acute outcome and follow-up from a large multicenter Italian clinical setting

Abstract Funding Acknowledgements Type of funding sources: None. Background Complete electrical pulmonary vein isolation (PVI) by cryo-balloon approach is a well-established ablation strategy of atrial fibrillation (AF). Recently, a new cryoablation system (POLARx) with unique features has been made available for clinical use. To date, limited data exist on acute and follow-up outcome of this system in a multicentric clinical practice. Purpose We reported the preliminary experience of this novel technology in a multicenter Italian registry. Methods Consecutive patients (pts) undergoing AF ablation from the CHARISMA registry at 6 Italian centres were included. Protocol-directed cryoablation was delivered for 180 sec or 240 sec according to operator’s preference for isolation achieved in ≤60 sec, or 240 sec if isolation occurred &amp;gt;60 sec or when time to isolation (TTI) was not available. The ablation endpoint was PV isolation as assessed by entrance and exit block. Rhythm monitoring during the follow-up examinations was performed via the clinical assessment of AF recurrence, ECG and Holter monitoring, according to the clinical practice of each center. All patients were followed-up for at least 6 months after the procedure. Arrhythmia recurrences within the first 3 months (blanking period) were classified as early recurrences and were not considered procedural failures Results Six-hundred twenty-four cryoapplications from 112 pts (439 PVs) were analyzed (n=89, 79.5% paroxysmal AF, n=23, 20.5% persistent AF, mean age 61.5±9 years, 76% male, 22% with an history of AT, mean LVEF 49±10%). PVI was achieved in all pts using only cryoablation. The mean number of freeze applications per pt was 5.6±2.1 (1.4±1.2 for LSPV, 1.5±1.1 for LIPV, 1.3±0.8 for RSPV and 1.3±0.8 for RIPV), with 318 (72.4%) PVs treated with a single cryoablation (92, 21% with 2 cryoablation; 29, 6.6% with more than 2 cryoablations). Fourty-four (39.3%) pts were treated with a single application to each of the PVs. Over a median of 296[245 to 382] days of follow-up, five (4.5%) patients experienced an early recurrence of AF/AT during the 90-day blanking period. Overall, 12 patients (10.7%) suffered an AF/AT recurrence after the 90-day blanking period (median time to recurrence 200[124 to 297] days). Specifically, 8 (7.1%) patients had AF recurrence only, 3 (2.7%) had AT recurrence only and 1 (0.9%) experienced both events. One (0.9%) patient underwent a repeated ablation procedure. The proportion of patients exhibiting AF/AT recurrences was similar between AF types (10 out 89, 11.2% for paroxysmal AF vs 2 out 23, 8.7% for persistent AF, p=1.00) with a hazard ratio of 0.9 (95%CI: 0.2 to 3.9, log-rank p=0.8894). One transient phrenic nerve palsy was observed, with full recovery in the 48-h post procedure; no major procedure-related adverse events were reported. Conclusion In this first multicentric experience, the novel cryo-balloon system proved to be safe and effective and resulted in a very low rate of AF/AT recurrence during follow-up.

PO-636-04 ABLATION OF ATRIAL FIBRILLATION BEYOND PULMONARY VEIN ISOLATION: DO ADDITIONAL ABLATION LESIONS IMPACT LEFT ATRIAL FUNCTION?

Electrical isolation of pulmonary veins (PVI) is a cornerstone for Atrial Fibrillation (AF) ablation therapy. Elimination of non-pulmonary vein (NPV) triggers in addition to PVI was shown to decrease long-term AF recurrence. The overall effect of AF ablation on left atrial (LA) function is poorly understood and it is unknown if additional ablation lesions can affect it. Our aim was to determine if LA function is different in patients after extensive LA ablation compared to PVI only. We hypothesized that addition of NPV ablation lesions in LA do not further deteriorate LA function compared to PVI alone. Out of consecutive 994 patients who underwent AF ablation at our center in years 2018-2019, we included 68 patients in our retrospective analysis who had echocardiograms (TTE) performed within 12 months prior to AF ablation and 1-12 months after. Redo ablations, history of mitral valve interventions were excluded. Patients were stratified into 2 groups: PVI only and PVI with additional LA ablation lesions (PVI+). Primary outcome was LA reservoir strain (LASr). We applied non-inferiority analysis with 90% CI for an overall alpha level of 0.05. Mean LASr in patients after AF ablation is reported 19 ±9%, we used a conservative 6% to define non-inferiority as a change in LASr. Patients in our study cohort had higher rates of history of HTN, HFrEF, DM, HLD, ESRD compared to all patients who underwent AF ablation. A higher rate of paroxysmal AF in the PVI only group was noted (70% vs 30%). The PVI+ group was observed to have a slightly higher increase in LASr compared to PVI alone (5.0%vs 4.3%), with 90% CI (-4.2 to 2.9). The upper bound for the true difference of 2.9% did not cross the pre-set margin of 6% (p<0.01 for test of non-inferiority). These findings were consistent when the LASr was adjusted for age, sex, hx of CAD, HLD, paroxysmal vs persistent AF, rhythm at pre-procedure TTE in a multivariable linear regression model, 90% CI (-5.46; 2.04), p<0.01. LA functional improvement evaluated by LASr is statistically non-inferior after PVI with additional LA ablation lesions compared to PVI alone. These findings were confirmed when adjusted for confounding clinical variables.

Incidence of epicardial connections between the right pulmonary vein carina and right atrium during catheter ablation of atrial fibrillation: A comparison between the conventional method and unipolar signal modification.

BackgroundWhen performing an electrical isolation of ipsilateral pulmonary veins (PVs) for atrial fibrillation, physicians often need additional radiofrequency (RF) ablation in the carina region between the superior and inferior PVs to achieve a right PV isolation because of intercaval bundles between the right PVs and right atrium (RA). We compared the efficacy of a high‐power and short‐duration ablation guided by unipolar signal modification (UM) with the conventional method (CM) for ablating epicardial connections between the right PV carina and RA.MethodsThe study subjects consisted of patients who underwent an initial box isolation of atrial fibrillation from January 2015 to December 2019 at Nara Medical University Hospital. Among these patients, 94 and 65 patients who met the criteria were assigned to the CM and UM groups, respectively. We retrospectively analyzed the anterior ablation line of the right PV using an electroanatomical mapping system. Patients whose initial ablation line included the right PV carina were excluded.ResultsSix and seven patients were, respectively, excluded from the CM and UM groups. Among 88 CM group patients, 21 needed additional right PV carina ablation, while among 58 UM group patients, 30 needed additional right PV carina ablation (p = .001). No anatomical factors were associated with the additional right PV carina ablation.ConclusionsCompared to the CM group, a box isolation was less achievable without RF ablation at the right PV carina in the UM group. We should consider a long‐duration ablation for epicardial connections between the right PV carina and RA.

Relation of biomarkers of inflammation, oxidative stress and fibrosis in patient with atrial fibrillation

Abstract Background Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in clinical practice. The patogenesis of AF is linked to an inflammatory reaction and oxidative stress that leads to fibrosis of the atria and progression of the disease. However, the role of different biomarkers in patients with AF is poorly defined. The purpose of this study is to define the role of several biomarkers of inflammation, oxidative stress and fibrosis (myeloperoxidase (MPO), high-sensitivity C-reactive protein (hsCRP), galectin-3 (Gal-3), oxidized low-density lipoprotein (oxLDL)) in patients with AF. Methods We included 75 patients with paroxysmal/persistent AF, who were admitted for electrical cardioversion or pulmonary vein isolation. MPO, hsCRP, Gal-3 and oxLDL were measured before the procedures. We compared the results with 75 healthy age-, sex- and blood pressure-matched individuals. Results Patients with AF had higher MPO (77.1 vs 41.7 ng/ml, p&amp;lt;0.001) compared the healthy subjects. There was also significantly higher hsCRP (3.7 vs 1.6 mg/L, p&amp;lt;0.001) and Gal-3 (12.3 vs 10.4 mg/L, p=0.003). No difference in oxLDL levels (78.8 vs 75.3 U/L, p=0.414) were seen (Table 1). MPO (β=0.012, p=0.014), hsCRP (β=0.213, p=0.046), and weight (β=0.037, p=0.006), were independently associated with AF in a logistic regression analysis (Table 2). Conclusions Patients with AF have increased markers of inflammation and fibrosis, whereas no increase in oxidative stress markers was detected. MPO, hsCRP and age weight were independently predictive of AF. These findings support the role of inflammatory and fibrotic mechanisms as important factors in the electrical and structural remodelling progress in the atria of patients with AF. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Estonian Research Council

Acute safety and performance outcomes from the inspIRE trial using a novel pulsed field ablation system for the treatment of paroxysmal atrial fibrillation

Abstract Background/Introduction The inspIRE clinical trial was designed to assess the safety and efficacy of a fully integrated biphasic pulsed field ablation (PFA) system comprised of a multi-channel generator, variable decapolar irrigated loop circular catheter, and mapping system (Figure A) for the treatment of paroxysmal atrial fibrillation (PAF). Purpose Using this novel PFA system in a multicentre clinical trial, we present the initial feasibility of electrical pulmonary vein isolation (PVI), procedural performance, and acute safety results. Methods inspIRE is a prospective, non-randomized, multi-centre study, planned to enrol up to 550 patients. PVI is performed with the novel, variable loop circular catheter, compatible mapping system and generator. Acute procedural effectiveness (entrance block in all clinically targeted PVs post adenosine/isoproterenol challenge) and the incidence of primary adverse events (PAEs) were assessed. PAEs are defined as the occurrence of cardiac tamponade/perforation, myocardial infarction, stroke/cerebrovascular accident, thromboembolism, transient ischemic attack, permanent phrenic nerve paralysis, pulmonary edema, pericarditis, and any major vascular access complications within 7 days of the ablation procedure. Additionally, any incidence of procedure or device related death, atrio-esophageal fistula, or PV stenosis (related to the ablation procedure or study catheter) within the 12M follow-up period is classified as a PAE. Results A total of 35 PAF subjects (age 59.7±10.7 years, 54.3% male) were treated across 5 European sites by 6 operators. Acute procedural success was achieved in 100% of study subjects (Figure B) with zero incidence of PAEs. Mean total procedure time was 82.9±19.9 minutes with 27.0±11.9 minutes of PFA from first to last application. Average fluoroscopy use was 10.6±6.8 minutes and LA dwell time was 45.6±15.3 minutes. Conclusion Initial results of the inspIRE trial demonstrate the acute safety and effectiveness of the new integrated IRE circular catheter, mapping system and generator for PVI in PAF patients. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): inspIRE is a company-sponsored study funded by Biosense Webster, Inc. Figure 1. (A) PFA System; (B) PVI Voltage Map

A Novel Visually Guided Radiofrequency Balloon Ablation Catheter for Pulmonary Vein Isolation: One-Year Outcomes of the Multicenter AF-FICIENT I Trial.

[Figure: see text].

B-PO03-103 PULMONARY VEIN ISOLATION THROUGH A NOVEL CRYO-BALLOON TECHNOLOGY IN A MULTICENTER CLINICAL SETTING: PRELIMINARY FINDINGS FROM THE CHARISMA REGISTRY

Complete electrical pulmonary vein isolation (PVI) by cryo-balloon is a well-established ablation strategy of atrial fibrillation (AF). Recently, a new cryoablation system (POLARx) with unique features has been made available for clinical use. No data exist on procedural characteristics of this system in a multicentric clinical practice. To characterize the preliminary experience of this novel technology in the Italian clinical practice. Consecutive patients (pts) undergoing AF ablation from the CHARISMA registry at 5 Italian centers were included. Protocol-directed cryoablation was delivered for 180 sec or 240 sec according to operator’s preference for isolation achieved in ≤60 sec, or 240 sec if isolation occurred >60 sec or when time to isolation (TTI) was not available. The ablation endpoint was PV isolation as assessed by entrance and exit block. Three-hundred thirty-six cryoapplications from 64 pts (254 PVs) were analyzed. PVI was achieved in all pts using only cryoablation. The mean number of freeze applications per pt was 5.2±1.5 (1.3±0.7 for LIPV, 1.4±1.1 for LSPV, 1.3±0.6 for RSPV and 1.3±0.5 for RIPV), with 197 (77.6%) PVs treated with a single cryoablation (43, 16.9% with 2 cryoablation; 14, 5.5% with more than 2 cryoablations). Twenty-four (37.5%) pts were treated with a single application to each of the PVs. The mean nadir temperature was -56 ± 6.8 °C and was colder than -50 °C in 84% of the PVs. TTI information was available in 158 (62.2%) PVs with a median TTI of 44 [31-67] sec (median temperature at TTI = -49 [-53 to -41] °C). Cryoablation was stopped early in 8 (2.4%) cases: in 3 times due to loss of capture of the phrenic nerve, in 3 cases for reaching a minimum temperature cut off (-65°C) and in the remaining 2 cases for operator’s choice. The mean time to target -40 °C (TTT) was 30.1 ± 7.2 sec with a TTT < 60 sec achieved in 99.1% of the cryoapplications; the mean thaw time to 0 °C was 19.1 ± 5.9 sec (thaw time >15 sec in 73.5% of the cryoapplications). No complications were observed at 30 days post-procedure. In this first multicentric experience in a clinical practice setting, the novel cryo-balloon system proved to be safe and effective and resulted in a high proportion of successful single-freeze isolation.

The role of a difference between target and actual ablation index values for first-pass point-by-point pulmonary vein isolation: results from a multicenter prospective registry

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): Ministry of Science and Higher Education grant (Russian Federation President Grant) Background/Introduction. Pulmonary vein electrical isolation (PVI) is a cornerstone of atrial fibrillation (AF) ablation. The Ablation Index (AI) aims to improve the efficacy and safety of radiofrequency (RF) PVI. First-pass isolation (FPI) is an indicator of PVI acute success. Target AI is being calculated for every operator as a mean value (usually, differently for anterior and posterior left atrial (LA) segments) following several "ideal" first-pass PVI procedures. However, adherence to target values, as well as its clinical importance, are unknown. Purpose. The aim of the present study was to evaluate the difference between the target and actual AI in the real practice. Methods. This work represents data from the Prospective Multicenter AF Ablation Registry. Data were collected using a web-based system. PVI procedures were performed according to the local practice, and RF ablation settings depended on operators’ preferences. Between January 2019 and December 2020, a total of 446 patients were enrolled from 7 centers, 407 of them underwent first-time AF ablation and were included into the analysis (mean age 61 ± 9 years old; 226 (55%) males; 313 (76%) with paroxysmal AF). FPI was determined as PVI achieved after circular ablation around PVs without additional applications plus persistence of bidirectional block over a 20-minute waiting period. Therefore, patients were divided in two groups: Group 1 (FPI, n = 242) and Group 2 (non-FPI, n = 165). Results. There was a significant difference between target (the mean target AI for the anterior LA segments was 438 ± 58 and 390 ± 27 for the posterior segments) and actually achieved mean AI (406 ± 33 for anterior segments and 389 ± 34 for posterior segments) with a greater difference for anterior segments (Δ 26 (95% CI [19; 32], p = 0,0001) than for posterior (Δ 4 (95% CI [0,2; 8], p = 0,042). The number of patients with a mean actual AI lower than a target value on the anterior and posterior LA walls was 219 (54%) and 171 (42%), respectively. In the FPI group higher mean values of target AI were present (FPI 444 ± 52 for anterior and 393 ± 27 for posterior LA segments vs non-FPI 432 ± 51 (p = 0,04) and 387 ± 23 (p = 0,01), respectively). The FPI group was characterized by higher mean actual AIs on anterior segments (FPI 410 ± 36 vs non-FPI 399 ± 25, p = 0,0001). There was no difference between groups in actual AI on the posterior wall (391 ± 27 vs 386 ± 41, p = 0,1). The non-FPI group was characterized by a higher proportion of subjects with hypertension (87% vs 69%, p = 0,0001) and a lower number of subjects with central obesity (body mass index≥30 in 48% vs 57%, p = 0,04). Conclusion(s). According to our prospective multicenter data, target AI is not achieved in a significant proportion of patients during PVI. This is associated with acute PV electrical reconduction and the necessity in additional ablations. FPI can be achieved more frequently when a higher mean AI value is achieved.

Comparing single approaches success in index atrial fibrillation ablation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Atrial Fibrillation (AF) ablation can be performed by inducing pulmonary vein electrical isolation. There are two widely used approaches: point-by-point and single-shot. Catheter AF ablation is effective in restoring and maintaining sinus rhythm. However, efficacy is limited by high rate of AF recurrence, after an initially successful procedure. Purpose To evaluate AF index ablation successfulness using single-shot techniques and compare them to conventional one (point-by-point using irrigated- tip ablation catheter). Methods We analyzed, from a single center, all patients submitted to an index AF ablation procedure and its successfulness. The last was defined as AF, atrial tachycardia or flutter recurrence (with a duration superior to 30seconds) event- free survival, determined by holter and/or event recorder. These exams were performed after 6 and 12months and then annually, until 5years post procedure were accomplished. Results From November 2004 to November 2020, 821patients were submitted to first AF ablation (male patients 67,2%(N = 552), mean age of 59 ± 12years old). Paroxysmal AF(PAF) was present in 62,9%(N = 516), with short-duration persistent AF in 21,8%(N = 179) and long-standing persistent in 15,3%(N = 126). Ablation techniques were irrigated tip catheter point-by-point (PbP)ablation in 266 patients (32,4%) and single-shot (SS)techniques on the remaining 555(67,6%), including PVAC in 294(35,8%),225(27,4%) submitted to cryoablation and 36(4,4%) to nMARQ. Globally, AF ablation had one-year success rate of 72,5%, and 56,2% at 3 years. A significant difference between AF duration type was found: Arrhythmic recurrence risk was 58% higher in persistent AF(PeAF) (HR 1.58;95%IC 1,22-2,04; p &amp;lt; 0.001). In patients presenting with PAF prior to the procedure, success was significantly higher in those submitted to SS technique(HR:0.69;95%CI 0,47-0,90;p = 0.046), while those with PeAF had similar results. Conclusion In this single center analysis almost three-quarters had achieved one-year event-free survival, and more than a half reached long-term freedom from atrial arrhythmia. Patients with paroxysmal atrial fibrillation submitted to single-shot procedure presented with a higher success-rate. Moreover, our study confirmed previous data on the importance of atrial fibrillation classification to postprocedural outcomes. Abstract Figure. Survival Curves

Novel cryo-balloon ablation technology for pulmonary vein isolation in patients with atrial fibrillation: preliminary experience from a multicenter clinical practice

Abstract Funding Acknowledgements Type of funding sources: None. Background Complete electrical pulmonary vein isolation (PVI) by cryo-balloon approach is a well-established ablation strategy of atrial fibrillation (AF). Recently, a new cryoablation system (POLARx) with unique features has been made available for clinical use. To date, no data exist on procedural characteristics of this system in a multicentric clinical practice. Purpose We aimed to characterize the initial experience of this technology in the Italian clinical practice. Methods Consecutive patients (pts) undergoing AF ablation from the CHARISMA registry at 5 Italian centres were included. Protocol-directed cryoablation was delivered for 180 sec or 240 sec according to operator’s preference for isolation achieved in ≤60 sec, or 240 sec if isolation occurred &amp;gt;60 sec or when time to isolation (TTI) was not available. The ablation endpoint was PV isolation as assessed by entrance and exit block. Results Two-hundred sixty-two cryoapplications from 49 pts (194 PVs) were analyzed. PVI was achieved with cryoablation only in all pts. The mean number of freeze applications per pt was 5.3 ± 1.5 (1.3 ± 0.6 for LIPV, LSPV and RSPV, 1.6 ± 1.3 for RIPV), with 143 (73.7%) PVs treated in a single-shot fashion (38, 19.6% with 2 shots; 13, 6.7% with more than 2 shots). Sixteen (33%) pts were treated with a single freeze to each of the PVs. The mean nadir temperature was -55.5 ± 6.9 °C and was colder than -50°C in 83% of the PVs. TTI information was evaluable in 120 (46%) cryoapplications with a median TTI of 47 [32-75] sec (median temperature at TTI = -49 [-53 to -42] °C). The mean time to target -40 °C (TTT) was 30.1 ± 6.9 sec with a TTT &amp;lt; 60 sec achieved in 99.2% of the cryoapplications; the mean thaw time to 0 °C was 18.6 ± 5.8 sec (thaw time &amp;gt;15 sec in 70.3% of the cryoapplications). The mean PV occlusion grade (rank 1-4) was 3.6 ± 0.6 (grade 2 in 5.2% of the cases, grade 3 in 25.6% and grade 4 in 69.2%). No complications were observed at 30 days post-procedure. Conclusion In this first multicentric experience in a clinical practice setting, the novel cryo-balloon system proved to be safe and effective and resulted in a high proportion of successful single-freeze isolation. Cooling parameters seem to be slightly different from reference cryo-balloon technology.

Latin-American experience in cryoablation of paroxysmal and persistent atrial fibrillation using second generation cryo-balloon. Acute success and 12 months of follow-up

ResumenObjetivo:La ablación por catéteres es una técnica habitual para tratar la fibrilación auricular (FA). Son escasos los datos prospectivos y multicéntricos con resultados a mediano plazo de la crioablación de venas pulmonares en América Latina. El objetivo es evaluar la seguridad y la eficacia de la ablación por criobalón de segunda generación en pacientes con FA paroxística o persistente en América Latina.Método:Se evaluaron las características del procedimiento y los resultados en agudo y a 12 meses Se incluyeron pacientes con FA mayores de 18 años a quienes se realizara desconexión de venas pulmonares con criobalón de segunda generación. Se definió como fallo al tratamiento cualquier episodio de FA, aleteo auricular o taquicardia auricular de más de 30 segundos fuera del periodo de cegamiento de 90 días.Resultados:Se incluyeron 218 pacientes (57 ± 11 años, 66.5% hombres, CHA2DS2-VASc 1.2 ± 1.1). Presentaron FA paroxística el 83.9%, FA persistente el 12.8% y FA persistente de larga duración el 2.3%. Quince pacientes presentaban antecedentes de aleteo auricular. Habían fracasado a una droga antiarrítmica el 89.4%. El éxito en agudo se obtuvo en 211 pacientes (96.8%). El tiempo promedio del procedimiento fue de 73.2 ± 26.7 minutos, el tiempo de fluoroscopia fue de 21.4 ± 23.9 minutos y el tiempo total de ocupación del laboratorio fue de 114.6 ± 41.3 minutos. Durante los 12 meses de seguimiento, el tiempo libre de recurrencia de FA fue del 88.6% en FA paroxística y del 73.1% en FA persistente. Veintiún pacientes (9.6%) presentaron eventos adversos relacionados con el procedimiento.Conclusiones:Estos resultados indican que la desconexión de venas pulmonares con criobalón es un tratamiento seguro y efectivo para la FA en América Latina.

Does pulsed field ablation regress over time? A quantitative temporal analysis of pulmonary vein isolation

The tissue specificity of pulsed field ablation (PFA) makes it an attractive energy source for pulmonary vein (PV) isolation (PVI). However, beyond each PFA lesion's zone of irreversible electroporation and cell death, there may be a surrounding zone of reversible electroporation and cell injury that could potentially normalize with time. The purpose of this study was to assess whether the level of electrical PVI that is observed acutely after PFA regresses over time. In a clinical trial, patients with paroxysmal atrial fibrillation underwent PVI using a biphasic PFA waveform delivered through a dedicated, variably deployable multielectrode basket/flower catheter. Detailed voltage maps were created using a multispline diagnostic catheter immediately after PFA and again ∼3 months later in a prospective, protocol-specified reassessment procedure. We analyzed 20 patients who underwent PFA with durable PVI and available maps from both time points. To compare the ablated zones, the left- and right-sided PV antral isolation areas and nonablated posterior wall area were quantified and the distances between left and right PV low-voltage edges were measured. A comparison of voltage maps immediately after PFA and at a median of 84 days (interquartile range 69-90 days) later revealed that there was no significant difference in either the left- and right-sided PV antral isolation areas or nonablated posterior wall area. The distances between low-voltage edges on the posterior wall were also not significantly different between the 2 time points. This study demonstrates that the level of PV antral isolation after PFA with a multielectrode PFA catheter persists without regression.

Atrial Fibrillation (Part 2) - Catheter Ablation.

ResumoApós mais de 20 anos desde sua utilização inicial, a ablação por cateter se tornou um procedimento rotineiramente realizado para tratamento de pacientes com fibrilação atrial (FA). Fundamentado inicialmente no isolamento elétrico das veias pulmonares em pacientes com FA paroxística, subsequentes avanços no entendimento da fisiopatologia levaram a técnicas adicionais não só para obter melhores resultados, mas também para tratar pacientes com formas persistentes de arritmia, assim como pacientes com cardiopatia estrutural e insuficiência cardíaca.

ST-Segment Elevation Associated with Mobitz II Atrioventricular Block During Transseptal Puncture for Atrial Fibrillation Ablation

Pulmonary veins electrical isolation as an invasive treatment of atrial fibrillation has been widely used in electrophysiology laboratories. This case report presents a rare and transient complication, during transseptal puncture for atrial fibrillation ablation. ST-segment elevation, hypotension and bradyarrhythmia related to catheterization were observed despite cineangiocoronariography without obstructive lesions. Clinical stability was achieved after administration of intravenous atropine and saline solution. It is speculated that the phenomenon is attributed to an increased vagal tone after the mechanical effect of transseptal puncture in the interatrial vagal network. The procedure was completed despite the phenomenon.

Association of the left common ostium with clinical outcome after pulmonary vein isolation in atrial fibrillation.

IntroductionElectrical pulmonary vein isolation (PVI) is used for the invasive treatment of atrial fibrillation (AF). However, despite the procedure’s technical evolution, the rate of AF recurrence due to electrical reconnection of the PVs is high. The aims of this study was to assess the influence of left common pulmonary venous ostium (LCO) on clinical outcomes following PVI.MethodsRetrospective cohort of 254 patients who underwent the first procedure of PVI from the years 2013–2018 was assessed. Patients with persistent AF of long duration and extra-pulmonary focus associated with triggers for arrhythmia were excluded. Patients were stratified into two groups according to the presence of a LCO and received follow up for atrial tachyarrhythmia-free survival. The mean follow-up period was 28 ± 1.73 months.ResultsThe majority were men (68.5%), with a mean age of 54 ± 12 years. With respect to the atrial anatomy, LCO occurred in 23.6% of cases after pulmonary venous angiotomography. The arrhythmia-free survival rate was 79.5% in the follow-up period. The Cox regression model was utilized and the adjusted hazard ratio for LCO was 0.36 (95% CI 0.15–0.87; p = 0.02) in terms of age, body mass index, left atrium diameter, bi-directional blocking of the cavotricuspid isthmus, persistent AF, left ventricular ejection fraction adjusted model.ConclusionAnatomic abnormality with the presence of the LCO is present in a quarter of patients undergoing AF ablation, which is associated with a lower rate of arrhythmia recurrence in our population.

Abstract 12973: Atrial Fibrillation is Associated With Increased Central Blood Pressure and Arterial Stiffness

Background: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in clinical practice, yet there is a lack of information about the hemodynamic profile and arterial stiffness of these patients. Purpose: The purpose of this study is to describe the differences in arterial stiffness and central blood pressures in patients with paroxysmal/persistent AF compared to a healthy control group. Methods: We included 76 patients with paroxysmal and persistent AF who underwent electrical cardioversion or pulmonary vein isolation (PVI) for AF. Carotid-femoral pulse wave velocity (cfPWV), augmentation index (AIx) and central blood pressure (cBP) were measured by applanation tonometry. All measurements were done in sinus rhythm (SR). We compared the results with 75 healthy age matched individuals. Results: Patients with a history of AF had higher cfPWV compared to the control group (8,0 m/s vs 7,2 m/s, p&lt;0,001). AF patients also had higher central systolic blood pressure (cSBP) (118 mmHg vs 114 mmHg, p=0,03) and central pulse pressure (cPP) (39 mmHg vs 37 mmHg, p=0,03), without differences in peripheral systolic pressure (pSBP) (127 mmHg vs 123 mmHg, p=0,13), peripheral diastolic blood pressure (pDPB) (78 mmHg vs 76 mmHg, p=0,14) and peripheral pulse pressure (pPP) (48 mmHg vs 47 mmHg, p=0,37). There was no difference in heart rate (HR) (58 vs 61 bpm, p=0,08) (Table 1). In a multiple regression analysis (adjusted R 2 = 0,37) where cfPWV was set as the dependent variable and adjusting for age, sex, HR, weight, mean central arterial pressure (cMAP), estimated glomerular filtration rate (eGFR), the AF group remained to be an independent predictor for cfPWV (p=0,016). Conclusions: Patients with atrial fibrillation have a higher cSBP, cPP and cfPWV compared to healthy subjects without differences in peripheral blood pressure and HR. These findings support the hypothesis that arterial stiffness may play an important role in the development of atrial fibrillation.